1. Field of the Invention
The present invention generally relates to a vehicle headrest apparatus that is used on a vehicle seat and supports the head of a seated passenger. More specifically, the present invention relates to a vehicle headrest apparatus that is configured to reliably restrain a passenger's head and suppress the rearward movement of a passenger's head when a rear-end collision occurs by actuating a headrest unit itself.
2. Background Information
An example of an automobile seatback system is disclosed in Japanese Laid-Open Patent Publication No. 7-291005 in which the seatback is designed to protect the head of a seated passenger in the event of a rear-end collision. In particular, this Japanese publication discloses a seatback that bears the dynamic load acting on a seated passenger due to the inertia force when a vehicle is subjected to a rear-end collision. The movement of a member that is displaced as a result is transmitted to a headrest support arm and the headrest unit moves toward the front of the vehicle. As a result, a large rearward movement of the seated passenger's head can be prevented.
Another example of an automobile seatback system is disclosed in Japanese Laid-Open Utility Model Patent Publication No. 6-59163. In the automobile seatback system of this publication, when a rear-end collision occurs, a sensor built into the seatback is depressed strongly by the inertia force of the seated passenger and an airbag is deployed from inside the headrest unit. As a result, even if a space exists between the neck area of the seated passenger and the headrest unit, the passenger's head can be prevented from moving rearward.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved a vehicle headrest apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.